feat(shareReplay): use another observable to control resets

This feature, first introduced for the share operator, is equally as desirable for the shareReplay operator.

Author: Evertt

src/internal/operators/shareReplay.ts

@@ -1,11 +1,12 @@
+import { Observable } from '../Observable';
 import { ReplaySubject } from '../ReplaySubject';
 import { MonoTypeOperatorFunction, SchedulerLike } from '../types';
 import { share } from './share';
 
 export interface ShareReplayConfig {
   bufferSize?: number;
   windowTime?: number;
-  refCount: boolean;
+  refCount: boolean | (() => Observable<any>);
   scheduler?: SchedulerLike;
 }